Diagnostic Test

Diagnostic Trouble Code (DTC) IS ACTIVE
1. Start the engine and allow it to reach normal operating temperature.
  WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
  
  NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.
2. Using the scan tool, select View DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
CHECKING AAT SENSOR
1. Turn the ignition off.
2. Disconnect the AAT sensor electrical connector.
3. Ignition on, engine not running.
4. Using the scan tool, read the AAT sensor voltage.
  NOTE: The sensor voltage should be approximately 5 Volts (plus or minus 0.1 volt) with the connector disconnected.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify there is good pin to terminal contact in the AAT sensor and Front Control Module (FCM) electrical connectors. Replace the AAT sensor if no problems were found with the connectors.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
(G31) AAT SIGNAL CIRCUIT SHORTED TO GROUND

Fig 1: Checking AAT Signal Circuit For Short To Ground
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the FCM C2 electrical connector.
3. Measure the resistance between ground and the (G31) AAT signal circuit in the AAT sensor electrical connector.
  Is the resistance less than 100 Ohms?
  
  Yes
  - Repair the short to ground in the (G31) AAT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
(G31) AAT SIGNAL CIRCUIT SHORTED TO THE (G931) SENSOR GROUND CIRCUIT

Fig 2: Checking Sensor Ground Circuit
Courtesy of CHRYSLER LLC
1. Measure the resistance between the (G931) sensor ground circuit and the (G31) AAT signal circuit in the AAT sensor electrical connector.
  Is the resistance less than 5.0 Ohms?
  
  Yes
  - Repair the short between the (G931) sensor ground circuit and the (G31) AAT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 5
EXCESSIVE RESISTANCE IN THE (G31) AAT SIGNAL CIRCUIT

Fig 3: Measuring Resistance Of AAT Sensor Signal Circuit From AAT Sensor Harness Connector To C2 FCM Harness Connector
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (G31) AAT signal circuit between the AAT sensor electrical connector and the FCM C2 electrical connector.
  Is the resistance less than 5.0 Ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the excessive resistance in the (G31) AAT Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
FRONT CONTROL MODULE (FCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the AAT sensor and the FCM.
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify there is good pin to terminal contact in the AAT sensor and FCM electrical.
4. Refer to any Technical Service Bulletins (TSBs) that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Replace and program the FCM in accordance with the Service Information.
  - Perform BODY VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .